961 gearbox

cliffa

VIP MEMBER
Joined
May 26, 2013
Messages
2,365
Country flag
I do intend to check the integrity of my clutch basket some time in the coming months and see if I can convert to the later gear lever style so can take a look then, but am reluctant to do so until Norton are open for spares.
 
Joined
Feb 4, 2020
Messages
350
Country flag
I do intend to check the integrity of my clutch basket some time in the coming months and see if I can convert to the later gear lever style so can take a look then, but am reluctant to do so until Norton are open for spares.
Just my 2 peneth, gearbox on my 961 is turning out sweet, just over 2000 miles. Still the clatter, clutch? at low revs but otherwise hunky dory!
 
  • Like
Reactions: MAK

Fast Eddie

VIP MEMBER
Joined
Oct 4, 2013
Messages
15,988
Country flag
I thought the gearbox and clutch were sweet on mine too.

What f***ing did my head in was the dreadful racket from the primary.

As a reasonably mechanically minded person (well at least I think so) that just never sounded ‘right’ to me at all, irrespective of how many times I was told ‘they all do that’ …

Jus’ cos they’re all wrong, don’t make it right!
 

Clive

VIP MEMBER
Joined
Jun 9, 2017
Messages
807
Country flag
I thought the gearbox and clutch were sweet on mine too.

What f***ing did my head in was the dreadful racket from the primary.

As a reasonably mechanically minded person (well at least I think so) that just never sounded ‘right’ to me at all, irrespective of how many times I was told ‘they all do that’ …

Jus’ cos they’re all wrong, don’t make it right!
Since my clutch rebuild/upgrade the snatching and shriek has gone but now I'm swapping between bikes the noise is even more apparent. It's basically something hitting something else hard which cannot be good for longevity.
 

Fast Eddie

VIP MEMBER
Joined
Oct 4, 2013
Messages
15,988
Country flag
Anyway back to the origin of the gearbox....
I’d suggest speaking to someone who’s actually been in a few.

Try PM‘ing Richard-7 on this forum, or emailing Ollie Thiel at Thiel Motorsports in Germany. It’s clearly not something the average owner / DIYer knows the answer to.
 
Joined
Jun 12, 2020
Messages
211
Country flag
Back onto the tangent that is the primary clatter. They had issues with the blacklash gear spring failing, so preload was reduced. That may have something to do with some of the noise.
 

BritTwit

VIP MEMBER
Joined
Aug 25, 2009
Messages
2,762
Country flag
As a reasonably mechanically minded person (well at least I think so) that just never sounded ‘right’ to me at all, irrespective of how many times I was told ‘they all do that’ …
In the beginning back in 2013 when my 961 arrived, it smoked like a house on fire when started cold. The factory told my dealer that "Oh, that's just because the rings are hard ones, and it takes time for them to seal.". When the dealer told me this I laughed at him, but he accepted that BS.
One of the design shortcomings of the 961 is that intermediate gear in the primary driving the balancer shaft. Even with a back lash spring it was a poor design choice by Dreer's team.
 

Fast Eddie

VIP MEMBER
Joined
Oct 4, 2013
Messages
15,988
Country flag
In the beginning back in 2013 when my 961 arrived, it smoked like a house on fire when started cold. The factory told my dealer that "Oh, that's just because the rings are hard ones, and it takes time for them to seal.". When the dealer told me this I laughed at him, but he accepted that BS.
One of the design shortcomings of the 961 is that intermediate gear in the primary driving the balancer shaft. Even with a back lash spring it was a poor design choice by Dreer's team.
That’s an interesting point. Given the bike has a 270 crank I’m wondering if the balance shaft was an afterthought?

I’ve said it before and this reinforces it… I wonder what a well balanced 961 would / could be like sans balance shaft?

Quieter and freer revving are probably a given. Just wonder if it could be smooth enough?
 
Last edited:

BritTwit

VIP MEMBER
Joined
Aug 25, 2009
Messages
2,762
Country flag
That’s an interesting point. Given the bike has a 270 crank I’m wondering if the balance shaft was an afterthought?

I’ve said it before and this reinforces it… I wonder what a well balanced 961 would / could be like sans balance shaft?

Quieter and faster are probably a given. Just wonder if it could be smooth enough?
Dreer's first attempt at a "new" design was with a new beefed up crankcase/crankshaft working through a separate HD gearbox. I think it was a 951, I can't recall. It was not a unit construction, and did not include provisions for a balancer shaft. That design was abandoned, and the 952 was created as a unit construction engine. So, I think the balancer was an essential part of the 952 design, not an afterthought. Just poorly executed.

It would be interesting to see what an 961 would be like without a balancer shaft. Of course the crank would need to be re-balanced by someone who knows what he is doing. The intermediate primary gear would have to be mounted on a jackshaft without balancer bob weights.
A nice project.
Any takers?
 
Joined
May 19, 2021
Messages
72
Country flag
I’d suggest speaking to someone who’s actually been in a few.

Try PM‘ing Richard-7 on this forum, or emailing Ollie Thiel at Thiel Motorsports in Germany. It’s clearly not something the average owner / DIYer knows the answer to.
Thanks, I will try that. The problem seems to be even those who have been inside cant seem to agree.
 

mean gene

VIP MEMBER
Joined
Dec 21, 2020
Messages
323
Country flag
Didn't someone say the clutch plate were Yamaha ? so if they used the entire clutch basket could it be splined for that?
 

cliffa

VIP MEMBER
Joined
May 26, 2013
Messages
2,365
Country flag
Didn't someone say the clutch plate were Yamaha ? so if they used the entire clutch basket could it be splined for that?
Yes, S. Bodycote, and I seem to remember EBC confirmed that to somebody on here (maybe Clive). R6 I think.
 
Joined
May 19, 2021
Messages
72
Country flag
Didn't someone say the clutch plate were Yamaha ? so if they used the entire clutch basket could it be splined for that?
Thats an interesting thought. The thing is there are only so many splines available and it would make sense to use something off the shelf.
 

cliffa

VIP MEMBER
Joined
May 26, 2013
Messages
2,365
Country flag
A picture from a well known auction site of a 2008 - 2016 R6 clutch. The splines definitely don't match the later shaft..

1623356972807.png
 

Clive

VIP MEMBER
Joined
Jun 9, 2017
Messages
807
Country flag
Didn't someone say the clutch plate were Yamaha ? so if they used the entire clutch basket could it be splined for that?
Nice idea and the plates may match the internals of the clutch basket but the outer with the ring gear and the inner sitting on the splines are totally different.
 

MAK

VIP MEMBER
Joined
Mar 15, 2018
Messages
310
Country flag
Nice idea and the plates may match the internals of the clutch basket but the outer with the ring gear and the inner sitting on the splines are totally different.
Did Thor motorcycles design an intermediate gear that did away with the backlash spring arrangement and use a sort of Cush drive arrangement.
I remember him mentioning it when I managed to get through.
Not sure if they offer a conversation at a price.
Could someone local check it out.
What is involved and how much?
 
Top